I did use it, but got some misfires on the more agressive maps and am not a do-it -yourselfer and don't and want to go through all the troubleshooting by replacing plugs and coils. My car has 46,000 miles and was a CPO, so don't know when the plugs were last changed. I've uninstalled it completely, it was only installed once. I was just looking for plug 'n play and didn't want to go through other modifications like exhausts or downpipes. The power boost was fantastic, though, and a throatier sound. I think you can install and uninstall these things over and over (Think I read that on Cobb's site).